As the speed of Internet traffic increases, on-demand television and video are becoming closer and closer to reality. The introduction of broadband networks, headend and terminal devices such as set-top boxes, and media such as DVD disks recorded with digitally compressed audio, video and data signals, for example, which utilize Motion Picture Expert Group (MPEG) compression standards, may provide sound and picture quality that is virtually indistinguishable from the original material. One of the most popular MPEG standards is MPEG-2, which provides the necessary protocols and infrastructure that may be used for delivering digital television or DVD contents with compressed audio, video and data signals. The MPEG-2 compression scheme compresses and packetize the video content into MPEG-2 packets. A detailed description of the MPEG-2 standard is published as ISO/IEC Standard 13818.
In addition to the increasing speed of Internet transactions, continued advancement of motion picture content compression standards permit high quality picture and sound while significantly reducing the amount of data that must be transmitted. A compression standard for television and video signals was developed by the Moving Picture Experts Group (MPEG), and is known as MPEG-2. An encoded bitstream, such as an MPEG-2 bitstream, comprises different types of data. For example, an MPEG-2 bitstream may comprise audio information, video information, and additional data. A transmitted MPEG-2 bitstream may be received by a set-top box (STB), for example, and the STB may further process the received bitstream. However, since the received bitstream comprises multiple types of data, the STB may utilize multiple decoders. Using multiple decoders to parse the received bitstream is time consuming and may result in processing delays. Furthermore, audio glitches may be generated during decoding when the transport stream input rate, or the played stream rate, may be different from the actual stream rate.
The implementation of fee-based video broadcasting may require a conditional access (CA) system to prevent non-subscribers and unauthorized users from receiving signal broadcasts. Cryptography algorithms may be utilized, for example, in content protection in digital set-top box systems and in other systems utilized in fee-based video broadcasting. Security keys may, therefore, play a significant part in the encryption and/or decryption process initiated by a cryptography algorithm. For each cryptography algorithm used in a fee-based video broadcasting system, for example, there may be a set of associated security keys that may be needed by the algorithm. Each PID channels from a particular program such as an audio PID, and/or a video PID, may have separate keys and key change points for each PID channel may be different. Since a set top box may support multiple programs, it needs to support multiple key change points. As the number of programs supported increases, it may become more burdensome for a processor the process large key change points.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.